Is Navio+ a "Shield" or "HAT"?

I read somewhere here that the Navio+ “added HAT support”, which according to the RasPi Foundation requires a ROM chip to be connected to GPIO0 and 1 (which then become reserved for reading the hardware ID and default pin configurations).

When writing the Windows drivers, I will try to check for such things to give some kind of plug and play. But to save wasting time, can @emlid4 please confirm:

  1. Is it really a “HAT”?
  2. If yes, what sort of data/file/Id should I get back when reading the ROM?
  3. Do you also provide the default hardware pin configuration (optional in the specification). Which would mean it would never be necessary to check and set the GPIO direction/resistance for “used” Navio+ pins. Also do you set any defaults for the other “free” pins.

Of course I’ll take time to read the whole HAT standard/firmware guide so I can get this sort of information. It appears the Windows IoT firmware does not expose this (but I will check properly) even though when explaining why the GPIO pins are reserved it mentions the firmware does something with it.


Navio+ is fully compliant with Raspberry Pi HAT standard, so it’s officially a HAT.

In the ROM we only store the manufacturer id, product id and revision. No pin configuration or anything else (all that stuff wasn’t really ready when we launched Navio+).

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Fantastic! :sunglasses: